Piggybacking tags are tags invoked by another tag (often called a container tag). Tags are those snippets of code your analytics, advertising, and other MarTech vendors have you install on your site so they can collect the data they need to operate.

One form of container tag you’re probably familiar with is the TMS container snippet. Which is not often considered in the context of tag piggybacking, in reality your tag management’s container snippet deploys piggybacking tags. Any tag that acts as a container for other tags uses piggybacking.

Piggybacking tags are most prevalent in the ad-serving community as a way for one ad server’s tag to invoke tags from other servers—allowing multiple tags to collect data without having to implement one another individually.

So in reality, piggybacking is common and can be quite useful, when it is used appropriately. But when mishandled, it can get out of control.

What Dangers Do Piggybacking Tags Pose?

Piggybacking tags can become dangerous because the third part can gain access to your website data and reduce your website’s performance. And these negative consequences can snowball: 

one vendor deploys a container, which deploys another container, and so on. As piggybacking tags daisy-chain downward with more and more tags, the following threats increase in likelihood:

Data leakage. Data leakage is the transmission of website data to an unauthorized party. As more and more tags appear on your site, more parties have access to your data, increasing the likelihood that your data could fall into the wrong hands.

Slow load times. Each piggybacking tag means an additional request to a server somewhere, increasing the load on your visitor’s connection and constricting bandwidth. The result: a slow website. Not ideal.

Data loss. Related to slow website load times, if your tags can’t load fast enough due to blocking piggybacking tags, you risk losing customer data.

Non-compliance. Especially in the wake of GDPR and CCPA, it’s important to make sure that data collection complies with both internal and external controls. Non-compliant data collection, tags, and cookies are more likely to happen if your website is heavy on piggybacking.